Modern jet aircraft commonly include a wing anti-icing system to keep the leading edges of the wings clear of ice. The atmospheric temperatures at altitude are well below freezing while visible moisture is present and without a wing anti-icing system, ice may form on the wing. This is undesirable.
Some wing anti-icing systems route hot air to the wing's leading edge to heat the leading edge and thereby inhibit the formation of ice. The source of the hot air for such wing anti-icing systems is bleed-air taken from the compressor section of the aircraft's jet engine. Bleed-air extracted from the compressor section can have a temperature of approximately five hundred degrees Fahrenheit. Using the bleed-air at this high temperature entails undesirable risks and complications. Furthermore, these risk and complications are unnecessary because five hundred degrees Fahrenheit is well above the temperature needed to keep the leading edge of the wing free of ice.
One common solution is to cool the bleed-air to a more manageable temperature before routing it to the wings. This is accomplished through the use of a pre-cooler. The pre-cooler receives the bleed air from the compressor. At the same time, the pre-cooler also receives a relatively high volume of cooling-air siphoned from the freestream flowing past the exterior of the aircraft. The free stream air is relatively cool (e.g., fifty degrees below zero, Fahrenheit) and in plentiful supply and therefore is well suited for cooling the bleed-air. By routing the bleed-air through a network of cooling pathways (e.g., ducts) and by passing the cooling-air around the cooling pathways, the temperature of the bleed-air is reduced down to a range of between two hundred to two hundred fifty degrees Fahrenheit. At the same time, the cooling-air is warmed to between eighty degrees and one hundred degrees Fahrenheit as it passes over the cooling pathways carrying the bleed-air. This warmed cooling-air exits the pre-cooler and is returned to the freestream.
In order to be effective at inhibiting the formation of ice, the hot air must be supplied to the wing anti-icing system at a relatively high volume. The siphoning of compressed air from the compressor in sufficient volume to operate the wing anti-icing system leaves less air in the engine for engine operations such as generation of thrust. This does not pose a problem in larger aircraft with larger engines. This is because larger engines produce a surplus of compressed air. As a result, they do not suffer an appreciable diminution in airflow to the combustion section of the engine and, therefore, do not suffer any significant power drain or diminution in thrust generation.
In smaller jet aircraft with smaller jet engines, however, there is a less generous supply of compressed air produced by the compressor section. Siphoning off compressed air from a small jet engine will leave an undesirably low supply of compressed air available to reach the combustion section of the engine. This, in turn, will reduce the thrust produced by the smaller jet engine. This may have a negative impact on the performance of the aircraft. This reduction in thrust during operation of the wing anti-icing system is undesirable.
Accordingly, it is desirable to provide an arrangement for supplying the wing anti-icing system with an adequate supply of heated air while minimizing the power drain experienced by the jet engine. In addition, it is desirable to provide a method for supplying the wing anti-icing system with an adequate supply of heated air while minimizing the power drain experienced by the jet engine. Furthermore, other desirable features and characteristics will become apparent from the subsequent summary and detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.